Table 2.

Normative reference intervals (95% CI) of IGF-1 measured by eight assay methods according to age range and sex in a cohort of 899 healthy subjects.

Age range	n	iSYS IGF-1 (ng/mL) 95%	LIAISON XL IGF-1 (ng/mL) 95%	IMMULITE 2000 IGF-1 (ng/mL) 95%	IGF-I-RIACT IGF-1 (ng/mL) 95%	Mediagnost ELISA IGF-1 (ng/mL) 95%	Mediagnost RIA IGF-1 (ng/mL) 95%	ROCHE Elecsys® IGF-1 (ng/mL) 95%	IMMULITE new standard IGF-1 (ng/mL) 95%
Males (years)
18–20	56	168–391	186–453	195–537	197–486	177–400	168–430	173–395	117–295
21–23	61	147–346	168–411	171–477	173–430	159–388	150–337	152–350	105–266
24–26	53	132–313	153–377	152–430	155–389	144–355	135–308	136–317	96–243
27–29	49	122–292	142–351	138–396	143–363	133–331	126–289	125–294	89–227
30–39	56	108–265	124–310	118–348	127–329	115–295	112–265	110–263	80–206
40–49	51	91–233	106–271	98–301	107–286	98–261	97–237	92–229	70–184
50–59	54	81–214	97–252	85–273	94–262	88–245	86–218	82–210	61–164
60–69	49	75–208	92–245	77–260	87–250	80–237	82–214	76–202	56–154
70–89	34	64–192	80–220	66–242	75–231	71–233	72–200	65–182	52–145
Females (years)
18–20	41	155–421	191–483	180–586	169–517	169–487	161–412	162–419	102–324
21–23	54	144–383	176–448	166–541	159–476	156–446	149–379	149–384	101–304
24–26	45	134–353	163–418	153–501	150–440	144–412	139–353	138–354	98–286
27–29	48	126–330	152–391	142–467	142–410	134–385	131–332	128–329	95–272
30–39	47	113–294	131–345	121–403	126–356	118–341	118–298	112–286	86–243
40–49	50	97–253	109–296	98–331	107–297	100–296	103–258	94–242	72–203
50–59	54	80–209	93–253	80–271	90–247	82–248	97–220	77–203	59–165
60–69	47	64–170	84–222	68–227	76–209	68–208	75–190	66–174	50–140
70–89	50	56–154	81–204	60–188	67–189	60–187	68–175	59–159	50–134